Can Police Dogs Really Sniff Out Drugs?

By Remy Melina |
January 6, 2011 11:00am ET

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A new analysis by the Chicago Tribune has called into question the
accuracy of drug-detecting dogs used during roadside traffic stops.
After examining three years of data for suburban departments, the
Tribune reported today (Jan. 6) that only 44 percent of sniffer dogs'
positive signals led to the actual discovery of drugs or paraphernalia.
The Tribune's analysis also shows that among drug alert roadside traffic
stops of Hispanic drivers, the sniffer dogs' success rate was 27
percent.

Detection dogs, which can also be trained to alert police to the
presence of explosives or blood, do not actually find the objects their
handlers are searching for – they just give off a signal, such as
scratching the ground or sitting down, to show that the contraband's scent is there. And, sometimes, all that's there is the scent.

"Like chalk dust that's left over after beating two blackboard
erasers together, the residual particles of narcotics can be left
behind," a representative for the New York State Police Department told
Life's Little Mysteries. "For example, leftover odor from pot can be
ground into the carpet. The dog can still smell its presence, even if
there's not enough of the drug there to convict someone."

The breeds selected
to train as sniffer dogs — typically German shepherds, Belgian Malinois
and Labrador retriever breeds — feature not only an impressive sense of
smell, but also strong hunting instincts. In the drug detection world,
that translates into an extremely high drive to seek out whatever they
have been trained to find, according to Anne Wills, owner of Dogs Finding Drugs,
a nonprofit that provides certified police canines for private
detection services – such as a concerned parent who wants to check their
child's room for drugs.

But don't think that the dogs' eagerness to find its target and please its master could be behind the false detections.
"The dogs' strong desire to hunt drives them to seek out what they've
been trained to find, so they do not falsely signal in order to get a
reward," Wills said. "In their minds, finding traces of a drug is the reward."

"These dogs and their handlers undergo extensive training for months
in order to be certified, because they work as a team," Wills continued.
"If I've got a dog that's not successful, it's because the dog was
trained wrong or is the wrong dog for the job because of its work ethic
and determination to hunt. Unsuccessful searches can also be the result
of an improperly trained handler. Both handlers and dogs have to be
well-trained because they are a true team."

States have varying certification and follow-up testing requirements
to ensure that sniffer dogs continue to detect drugs accurately. Some
states retest the dogs
and their handlers (dogs typically stay assigned to the handler they
were trained with and the team gets retested together) once every three
years, while require annual or biannual tests.

Rather than grading dogs and handlers by success rate, they are
tested on a strict pass or fail basis. Initial training of the team
takes approximately five months, at the end of which they are tested,
and follow-up tests take about a week, according to the NYPD.